1. Field of the Invention
The present invention relates to a technique for controlling an amount of light emitted from a light emission device of an image pickup apparatus.
2. Description of the Related Art
Conventionally, there has been known a technique for controlling amounts of light emitted from flash devices during photographing using a master flash device directly coupled to a camera and at least one slave flash device disposed apart from the master flash device (see, Japanese Laid-open Patent Publication No. 2000-89307).
In this technique, unidirectional communication from the master flash device to the slave flash device is used for control of light emission.
Therefore, even if the slave flash device cannot emit the amount of light requested by the master flash device at multiple flash photographing, the master flash device cannot recognize that fact. As a result, photographing cannot be performed at light amount ratios between the flash devices set by the user, making it difficult to obtain a picked-up image intended by the user.